scholarly journals Simvastatin impairs hippocampal synaptic plasticity and cognitive function in mice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yujun Guo ◽  
Guichang Zou ◽  
Keke Qi ◽  
Jin Jin ◽  
Lei Yao ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Cognitive Function ◽  
Memory Function ◽  
Long Term Potentiation ◽  
Drug Discontinuation ◽  
Hippocampal Synaptic Plasticity ◽  
Term Potentiation ◽  
The Central Nervous System

AbstractLipophilic statins which are blood brain barrier (BBB) permeable are speculated to affect the cholesterol synthesis and neural functions in the central nervous system. However, whether these statins can affect cholesterol levels and synaptic plasticity in hippocampus and the in vivo consequence remain unclear. Here, we report that long-term subcutaneous treatments of simvastatin significantly impair mouse hippocampal synaptic plasticity, reflected by the attenuated long-term potentiation of field excitatory postsynaptic potentials. The simvastatin administration causes a deficiency in recognition and spatial memory but fails to affect motor ability and anxiety behaviors in the mice. Mass spectrometry imaging indicates a significant decrease in cholesterol intensity in hippocampus of the mice receiving chronic simvastatin treatments. Such effects of simvastatin are transient because drug discontinuation can restore the hippocampal cholesterol level and synaptic plasticity and the memory function. These findings may provide further clues to elucidate the mechanisms of neurological side effects, especially the brain cognitive function impairment, caused by long-term usage of BBB-permeable statins.

scholarly journals Simvastatin Impairs Hippocampal Synaptic Plasticity and Cognitive Function in Mice

2020 ◽  
Author(s):  
Yujun Guo ◽  
Guichang Zou ◽  
Jin Jin ◽  
Lei Yao ◽  
Keke Qi ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Cognitive Function ◽  
Memory Function ◽  
Long Term Potentiation ◽  
Drug Discontinuation ◽  
Hippocampal Synaptic Plasticity ◽  
Term Potentiation ◽  
The Central Nervous System

Abstract Lipophilic statins which are blood brain barrier (BBB) permeable are speculated to affect the cholesterol synthesis and neural functions in the central nervous system. However, whether these statins can affect cholesterol levels and synaptic plasticity in hippocampus and the in vivo consequence remain unclear. Here, we report that long-term subcutaneous treatments of simvastatin significantly impair mouse hippocampal synaptic plasticity, reflected by the attenuated long-term potentiation of field excitatory postsynaptic potentials. The simvastatin administration causes a deficiency in recognition and spatial memory but fails to affect motor ability and anxiety behaviors in the mice. Mass spectrometry imaging indicates a significant decrease in cholesterol intensity in hippocampus of the mice receiving chronic simvastatin treatments. Such effects of simvastatin are transient because drug discontinuation can restore the hippocampal cholesterol level and synaptic plasticity and the memory function. These findings may provide further clues to elucidate the mechanisms of neurological side effects, especially the brain cognitive function impairment, caused by long-term usage of BBB-permeable statins.

scholarly journals Simvastatin Impairs Hippocampal Synaptic Plasticity and Cognitive Function in Mice

2021 ◽  
Author(s):  
Yujun Guo ◽  
Guichang Zou ◽  
Keke Qi ◽  
Jin Jin ◽  
Lei Yao ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Memory Function ◽  
Long Term Potentiation ◽  
Drug Discontinuation ◽  
Cholesterol Levels ◽  
Hippocampal Synaptic Plasticity ◽  
Term Potentiation ◽  
The Central Nervous System

Abstract Lipophilic statins which are blood brain barrier (BBB) permeable are speculated to affect the cholesterol synthesis and neural functions in the central nervous system. However, whether these statins can affect cholesterol levels and synaptic plasticity in hippocampus and the in vivo consequence remain unclear. Here, we report that long-term subcutaneous treatments of simvastatin significantly impair mouse hippocampal synaptic plasticity, reflected by the attenuated long-term potentiation of field excitatory postsynaptic potentials. The simvastatin administration causes a deficiency in recognition and spatial memory but fails to affect motor ability and anxiety behaviors in the mice. Mass spectrometry imaging indicates a significant decrease in cholesterol intensity in hippocampus of the mice receiving chronic simvastatin treatments. Such effects of simvastatin are transient because drug discontinuation can restore the hippocampal cholesterol level and synaptic plasticity and the memory function. These findings may provide further clues to elucidate the mechanisms of neurological side effects, especially the brain cognitive

scholarly journals Effects of the hydroalcoholic extract of Rosa damascena on hippocampal long-term potentiation in rats fed high-fat diet

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Seyed Asaad Karimi ◽  
Somayeh Komaki ◽  
Masoumeh Taheri ◽  
Ghazaleh Omidi ◽  
Masoumeh Kourosh-Arami ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Long Term Potentiation ◽  
Rosa Damascena ◽  
High Fat ◽  
Oxidative Stress Biomarkers ◽  
Hydroalcoholic Extract ◽  
Hippocampal Synaptic Plasticity ◽  
Term Potentiation

AbstractHigh-fat diets (HFDs) and obesity can cause serious health problems, such as neurodegenerative diseases and cognitive impairments. Consumption of HFD is associated with reduction in hippocampal synaptic plasticity. Rosa damascena (R. damascena) is traditionally used as a dietary supplement for many disorders. This study was carried out to determine the beneficial effect of hydroalcoholic extract of R. damascena on in vivo hippocampal synaptic plasticity (long-term potentiation, LTP) in the perforant pathway (PP)—dentate gyrus (DG) pathway in rats fed with an HFD. Male Wistar rats were randomly assigned to four groups: Control, R. damascena extract (1 g/kg bw daily for 30 days), HFD (for 90 days) and HFD + extract. The population spike (PS) amplitude and slope of excitatory post-synaptic potentials (EPSP) were measured in DG area in response to stimulation applied to the PP. Serum oxidative stress biomarkers [total thiol group (TTG) and superoxide dismutase (SOD)] were measured. The results showed the HFD impaired LTP induction in the PP-DG synapses. This conclusion is supported by decreased EPSP slope and PS amplitude of LTP. R. damascena supplementation in HFD animals enhanced EPSP slope and PS amplitude of LTP in the granular cell of DG. Consumption of HFD decreased TTG and SOD. R. damascena extract consumption in the HFD animals enhanced TTG and SOD. These data indicate that R. damascena dietary supplementation can ameliorate HFD-induced alteration of synaptic plasticity, probably through its significant antioxidant effects and activate signalling pathways, which are critical in controlling synaptic plasticity.

Brivaracetam Prevents the Over-expression of Synaptic Vesicle Protein 2A and Rescues the Deficits of Hippocampal Long-term Potentiation In Vivo in Chronic Temporal Lobe Epilepsy Rats

2020 ◽  
Vol 17 (4) ◽  
pp. 354-360 ◽  
Author(s):  
Yu-Xing Ge ◽  
Ying-Ying Lin ◽  
Qian-Qian Bi ◽  
Yu-Juan Chen
Keyword(s):  
Synaptic Plasticity ◽  
Temporal Lobe Epilepsy ◽  
Synaptic Vesicle ◽  
Long Term Potentiation ◽  
Synaptic Dysfunction ◽  
Over Expression ◽  
Term Potentiation ◽  
Synaptic Vesicle Protein 2A

Background: Patients with temporal lobe epilepsy (TLE) usually suffer from cognitive deficits and recurrent seizures. Brivaracetam (BRV) is a novel anti-epileptic drug (AEDs) recently used for the treatment of partial seizures with or without secondary generalization. Different from other AEDs, BRV has some favorable properties on synaptic plasticity. However, the underlying mechanisms remain elusive. Objective: The aim of this study was to explore the neuroprotective mechanism of BRV on synaptic plasticity in experimental TLE rats. Methods: The effect of chronic treatment with BRV (10 mg/kg) was assessed on Pilocarpine induced TLE model through measurement of the field excitatory postsynaptic potentials (fEPSPs) in vivo. Differentially expressed synaptic vesicle protein 2A (SV2A) were identified with immunoblot. Then, fast phosphorylation of synaptosomal-associated protein 25 (SNAP-25) during long-term potentiation (LTP) induction was performed to investigate the potential roles of BRV on synaptic plasticity in the TLE model. Results: An increased level of SV2A accompanied by a depressed LTP in the hippocampus was shown in epileptic rats. Furthermore, BRV treatment continued for more than 30 days improved the over-expression of SV2A and reversed the synaptic dysfunction in epileptic rats. Additionally, BRV treatment alleviates the abnormal SNAP-25 phosphorylation at Ser187 during LTP induction in epileptic ones, which is relevant to the modulation of synaptic vesicles exocytosis and voltagegated calcium channels. Conclusion: BRV treatment ameliorated the over-expression of SV2A in the hippocampus and rescued the synaptic dysfunction in epileptic rats. These results identify the neuroprotective effect of BRV on TLE model.

Neuronal calcium sensors and synaptic plasticity

2009 ◽  
Vol 37 (6) ◽  
pp. 1359-1363 ◽  
Author(s):  
Mascia Amici ◽  
Andrew Doherty ◽  
Jihoon Jo ◽  
David Jane ◽  
Kwangwook Cho ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Long Term Potentiation ◽  
Signalling Pathways ◽  
Calcium Sensor ◽  
Calcium Sensors ◽  
Term Potentiation ◽  
Neuronal Calcium Sensor Protein ◽  
The Central Nervous System ◽  
Sensor Proteins

Calcium entry plays a major role in the induction of several forms of synaptic plasticity in different areas of the central nervous system. The spatiotemporal aspects of these calcium signals can determine the type of synaptic plasticity induced, e.g. LTP (long-term potentiation) or LTD (long-term depression). A vast amount of research has been conducted to identify the molecular and cellular signalling pathways underlying LTP and LTD, but many components remain to be identified. Calcium sensor proteins are thought to play an essential role in regulating the initial part of synaptic plasticity signalling pathways. However, there is still a significant gap in knowledge, and it is only recently that evidence for the importance of members of the NCS (neuronal calcium sensor) protein family has started to emerge. The present minireview aims to bring together evidence supporting a role for NCS proteins in plasticity, focusing on emerging roles of NCS-1 and hippocalcin.

Nicotine Enhances the Depressive Actions of Aβ1–40 on Long-Term Potentiation in the Rat Hippocampal CA1 Region In Vivo

2003 ◽  
Vol 89 (6) ◽  
pp. 2917-2922 ◽  
Author(s):  
D. B. Freir ◽  
C. E. Herron
Keyword(s):  
Synaptic Plasticity ◽  
Long Term Potentiation ◽  
Α7 Nicotinic Acetylcholine Receptor ◽  
High Affinity ◽  
Ca1 Region ◽  
Α7 Nachr ◽  
Term Potentiation ◽  
Significant Depression

Hippocampal long-term potentiation (LTP) is a form of synaptic plasticity used as a cellular model of memory. Beta amyloid (Aβ) is involved in Alzheimer's disease (AD), a neurode-generative disorder leading to cognitive deficits. Nicotine is also claimed to act as a cognitive enhancer. Aβ is known to bind with high affinity to the α7-nicotinic acetylcholine receptor (nAChR). Here we have investigated the effect of intracerebroventricular (icv) injection of the endogenous peptide Aβ1–40 on LTP in area CA1 of urethananesthetized rats. We also examined the effect of Aβ12–28 (icv), which binds with high affinity to the α7-nAChR and the specific α7-nAChR antagonist methyllycaconitine (MLA) on LTP. We found that Aβ12–28 had no effect on LTP, whereas MLA depressed significantly LTP, suggesting that activation of the α7-nAChR is a requirement for LTP. Within the in vivo environment, where other factors may compete with Aβ12–28 for binding to α7-nAChR, it does not appear to modulate LTP. To determine if the depressive action of Aβ1–40 on LTP could be modulated by nicotine, these agents were also co-applied. Injection of 1 or 10 nmol Aβ1–40 caused a significant depression of LTP, whereas nicotine alone (3 mg/kg) had no effect on LTP. Co-injection of nicotine with Aβ1–40 1 h prior to LTP induction caused a further significant depression of LTP compared with Aβ1–40 alone. These results demonstrate that nicotine enhances the deficit in LTP produced by Aβ1–40. This then suggests that nicotine may exacerbate the depressive actions of Aβ on synaptic plasticity in AD.

scholarly journals Widespread promoter methylation of synaptic plasticity genes in long-term potentiation in the adult brain in vivo

BMC Genomics ◽  
2017 ◽  
Vol 18 (1) ◽  
Author(s):  
Jesper L. V. Maag ◽  
Dominik C. Kaczorowski ◽  
Debabrata Panja ◽  
Timothy J. Peters ◽  
Clive R. Bramham ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Promoter Methylation ◽  
Long Term Potentiation ◽  
Adult Brain ◽  
Term Potentiation

Hippocampal synaptic plasticity in neurodegenerative diseases: Aß, tau and beyond

Neuroforum ◽  
2018 ◽  
Vol 24 (3) ◽  
pp. A133-A141
Author(s):  
Detlef Balschun ◽  
Michael J. Rowan
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Synaptic Plasticity ◽  
Long Term Potentiation ◽  
Hippocampal Synaptic Plasticity ◽  
Term Potentiation ◽  
Neurological Illnesses ◽  
Early Alzheimer’S Disease ◽  
Opposing Effects

Abstract The study of long-term potentiation (LTP) and long-term depression (LTD) in disease models provides essential mechanistic insight into synaptic dysfunction and remodelling in many neuropsychiatric and neurological illnesses. The ability of misfolded forms of the two key proteins of Alzheimer’s disease, amyloid ß (Aß) and the microtubule binding tau to disrupt hippocampal synaptic plasticity, engender highly sensitive litmus tests of impending synaptic failure and subsequent structural pathology. Many transgenic and injection-induced rodent models show rapid and persistent inhibition of LTP, and sometimes opposing effects of Aß and tau on LTD. Intriguingly, both intracellular and extracellular actions of these proteins are implicated. Both directly targeting these proteins and abrogating their synaptotoxic actions are being explored to redress the insidious shift from physiological to pathological plasticity in early Alzheimer’s disease.

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